WASHINGTON — The Army general in charge of the Trump administration's controversial border mission is interested in beginning to redeploy some of the U.S. troops who were dispatched several weeks ago to assist Customs and Border Protection, U.S. military officials said Monday.

The shift would come as the military seeks to adjust to realities on the ground, where soldiers have spent days stringing miles of barbed concertina wire and some have said that they spent days waiting for assignments. They were sent to the border in the days leading up to the Nov. 6 midterm election, as President Donald Trump said he wanted to stop an "invasion" of migrants who were traveling north in a caravan from Central America.

Lt. Gen. Jeffrey Buchanan said in an interview with Politico on Monday that he would likely focus first on redeploying some soldiers focused on logistics. They comprise the majority of the border force, and have focused both on installing concertina and other barriers to slow down any rush of migrants, and building temporary camps in which U.S. soldiers can live nearby. U.S. military officials, speaking on the condition of anonymity due to the sensitivity of the subject, confirmed the comment is accurate.

"Now that things are set down here, we don't need as many troops to actually build base camps and things like that, because the base camps are built," said Buchanan, who has headquarters in San Antonio.

Critics of the operation, including some retired generals, have decried the effort as a cynical attempt by the president to rally his conservative base to vote. Defense Secretary Jim Mattis and other defense officials have defended it as legal, with Mattis saying that in the military, "we don't do stunts."

It's unclear how quickly the troops will begin returning home, and whether any could be reassigned from Texas or Arizona to California, following a recent decision by members of the caravan to turn west and head to Tijuana, Mexico, just south of San Diego. The migrants began arriving in Tijuana last week.

Presently, there are about 5,800 servicemembers deployed to the border for the mission, including about 2,800 in Texas, 1,500 in California and 1,500 in Arizona. Buchanan said that the number of servicemembers involved in the mission should fall quickly as they finish their work, Politico reported.

U.S. military officials have said repeatedly that they expect the entire mission to conclude by Dec. 15, with the caveat that circumstances could change. Prior to the election, Trump said that he could send as many 15,000 troops, but military officials said subsequently that is unlikely.

In South Texas, about 1,000 soldiers were sent to the border, some 1,500 miles away from where the migrants are now heading. When The Washington Post visited a base camp near the border in the town of Donna on Nov. 10, more than 100 soldiers could be seen relaxing inside a large tent about the size of a hockey rink, with some playing video games, others tossing around a football, and others reading.

Among the questions that soldiers have asked during the deployment is whether they themselves will be directed to eventually take down the miles of concertina wire they installed. On Nov. 14, Mattis told a soldier who asked that question that the mission so far was to install the barriers, and "we'll let you know" what the ultimate plan is.

Mattis has sought to characterize the mission as legal and routine in nature.

"We determined that the mission was absolutely legal, and this was also reviewed by Department of Justice lawyers," Mattis said. "It's obviously a moral and ethical mission to support our border patrolmen. There's nothing new under the sun."